Process for manufacturing tyres for vehicle wheels

ABSTRACT

In a process for manufacturing tyres for vehicle wheels, including building, on a toroidal support, a carcass structure including at least one carcass ply associated, at axially opposite end edges thereof, with annular anchoring structures, the step of building the carcass structure includes forming at least one reinforcing structure, operatively associated with the annular anchoring structures through deposition on the toroidal support of at least one reinforcing element at a deposition region defined on the toroidal support. The deposition of the at least one reinforcing element includes the steps of providing at least one reinforcing element having a length determined as a function of the length of the deposition region; deforming the at least one reinforcing element to form an annular reinforcing element having a shape substantially corresponding to the shape of the deposition region; and depositing the annular reinforcing element at the deposition region. An apparatus for carrying out such a process is also described.

The present invention relates to a process for manufacturing tyres forvehicle wheels.

The invention also relates to an apparatus for the deposition of atleast one reinforcing element on a toroidal support, said apparatusbeing able to be used to carry out the aforementioned process.

In the present description and in the subsequent claims, the term“reinforcing element” is used to indicate an element comprising one ormore thread-like reinforcing elements, such as textile or metalliccords, incorporated in, or coated with, a layer of elastomeric material.

It should also be specified that, in the present description and in thesubsequent claims, the term: elastomeric material, is used to indicate acomposition comprising at least one elastomeric polymer and at least onereinforcing filler. Preferably, such a composition also comprisesadditives like, for example, a cross-linking agent and/or a plasticiser.Thanks to the provision of the cross-linking agent, such a material canbe cross-linked through heating, so as to form the final product.

A tyre for vehicle wheels generally comprises a carcass structurecomprising at least one carcass ply formed from reinforcing cordsincorporated in an elastomeric matrix. The carcass ply has end edgesrespectively engaged with annular anchoring structures, arranged in theareas usually identified with the name “beads” and normally each formedfrom a substantially circumferential annular insert on which at leastone filling insert is applied, in a radially outer position thereof.Such annular structures are commonly referred to as “beads cores” andhave the task of keeping the tyre well fixed to the anchoring seatspecifically provided in the rim of the wheel, thus avoiding inoperation the radially inner end edge of the tyre coming out from such aseat.

At the beads specific reinforcing structures can be provided having thefunction of improving the torque transmission to the tyre. The region ofthe beads, indeed, is particularly active in the torque transmissionfrom the rim to the tyre when accelerating and when braking and,therefore, the provision of appropriate reinforcing structures in thisarea ensures that the torque transmission occurs with the maximumpossible reactivity.

In a radially outer position with respect to the carcass ply a beltstructure comprising one or more belt layers is associated, said beltlayers being arranged radially one on top of the another and havingtextile or metallic reinforcement cords with crossed orientation and/orsubstantially parallel to the direction of circumferential extension ofthe tyre.

Between the carcass structure and the belt structure a layer ofelastomeric material can be provided, known as “under-belt”, having thefunction of making the radially outer surface of the carcass structureas uniform as possible for the subsequent application of the beltstructure.

In a radially outer position with respect to the belt structure a treadband is applied, also made from elastomeric material like otherstructural elements making up the tyre.

Between the tread band and the belt structure a so-called “under-layer”of elastomeric material can be arranged, said layer having propertiessuitable to ensure a steady union of the tread band itself.

On the side surfaces of the carcass structure respective sidewalls ofelastomeric material are also applied, each extending from one of theside edges of the tread band up to the respective annular anchoringstructure to the beads.

Conventional manufacturing processes of tyres for vehicle wheelsessentially provide for the components of the tyre listed above to befirstly made separately from each other, to then be assembled in asubsequent building step of the tyre.

Nevertheless the current tendency is that of using manufacturingprocesses that allow the production and storage of semi-finishedproducts to be minimised, or possibly eliminated.

More specifically, attention has now turned towards process solutionsthat allow the individual components of the tyre to be made by directlyapplying them, according to a predetermined sequence, onto the tyrebeing built on a forming support, typically toroidal or cylindrical.

For example, in document WO 01/36185 to the same Applicant, thecomponents of the tyre are made on a toroidal support by sequentiallydepositing a plurality of reinforcing elements thereon, the reinforcingelements consisting for example of individual rubberised cords or ofrubberised cords grouped in parallel in the form of strip-like elements,particularly used in making the carcass and belt structure, and ofcontinuous elongate elements in elastomeric material, particularly usedfor making the other structural components of the tyre, such as forexample tread band, sidewalls, liners, fillers.

Document U.S. Pat. No. 6,355,126 describes for example a method and anapparatus for making a belt layer through deposition on a suitablypositioned forming support of band-like pieces cut from a continuousband-like element. The band-like pieces, once cut from the continuousband-like element, are picked up through gripping means and moved to theforming support for deposition.

In EP 1 418 043 A2 a method and an apparatus for forming an annularelastomeric component of a tyre, in particular an insert for filling thebeads, are described. The described method comprises an annularextrusion step of elastomeric material on a forming support and amodelling step, through the action of a modelling extruder on thesurface of the forming support, of the material deposited to obtain thedesired profile for the component.

In U.S. Pat. No. 6,379,493 B1 a device for the transportation anddeposition onto a forming support of a tyre of cut to size pieces ofelastomeric material is described, said pieces being in particularintended to form inserts for filling the beads. The device comprisesrotatable gripping devices which are movable along a directionessentially tangential to the circumferential surface of the formingdrum and allow each piece to be gripped and deposited in a predeterminedposition on the forming drum.

With particular reference to the region of the tyre defined at the bead,the Applicant has realised the importance of providing in this region areinforcing structure, as described with reference to the tyre structurediscussed above.

The Applicant has considered the problem of making and applying, on asubstantially toroidal forming support, a reinforcing structurecomprising one or more reinforcing element in the region of the bead ofthe tyre in a process for producing tyres for example of the typedescribed in document WO 01/36185 previously mentioned.

The Applicant has verified the possibility of forming on a substantiallytoroidal forming support a reinforcing structure as described above byapplying at least one reinforcing element on a substantially annulardeposition region defined on said toroidal support, said depositionregion for example being able to be defined at the region of the bead ona surface of the forming support that is not perfectly planar.

The Applicant has also verified the possibility of carrying out theaforementioned application while maintaining the maximum possibleflexibility in terms of diameter and thickness of the reinforcingelement and inclination of the thread-like reinforcing elementsincorporated therein, ensuring high structural homogeneity along thedirection of circumferential extension of the tyre and at the same timeavoiding the formation of possible defects on the tyre, such as forexample overlapping or undesired spaces in the reinforcing structure.This allows a deposition according to the design to be ensured and thusallows increasingly high quality and performance levels of the tyre tobe ensured.

The Applicant has found that by depositing a reinforcing elementdeformed so that its shape substantially corresponds to the shape of thedeposition region onto a toroidal forming support of a tyre, at asubstantially annular deposition region, it is possible to obtain a tyrebuilt substantially without defects in the region of the bead even withcomplex design geometries of the tyre itself.

The present invention therefore relates, in a first aspect thereof, to aprocess for manufacturing tyres for vehicle wheels, comprising buildingon a toroidal support a carcass structure comprising at least onecarcass ply associated, at axially opposite end edges thereof, withannular anchoring structures;

wherein the step of building said carcass structure comprises forming atleast one reinforcing structure, operatively associated with saidannular anchoring structures through deposition on the toroidal supportof at least one reinforcing element at a deposition region defined onthe toroidal support;wherein the step of depositing the at least one reinforcing elementcomprises the steps of:

-   -   providing at least one reinforcing element having a length        determined as a function of the length of the deposition region;    -   deforming the at least one reinforcing element to form an        annular reinforcing element having a shape substantially        corresponding to the shape of the deposition region;    -   depositing the annular reinforcing element at the deposition        region.

In the present description and in the subsequent claims, the expression“length of the deposition region” referred to a substantially annulardeposition region indicates the length of the longitudinal developmentof such a region.

Advantageously, the process of the present invention, in a process formanufacturing tyres for example of the type described in document WO01/36185, allows a reinforcing structure to be made that issubstantially homogeneous and uniform, in particular circumferentially,at the bead region of the tyre. This is achieved by deforming the wholereinforcing element, previously provided with a length determined as afunction of the length of the deposition region, so as to give it anannular shape substantially corresponding to that of the depositionregion, and then depositing the deformed reinforcing element.Furthermore, this result is achieved substantially irrespective of thesize of the deposition region, the width of the reinforcing element andthe arrangement of thread-like reinforcing elements present inside thereinforcing element.

It is thus possible to make on a toroidal forming support a tyrereinforced at the bead region having high quality levels and,consequently, high performance.

In a preferred embodiment of the process of the invention, the step ofproviding the at least one reinforcing element comprises the steps of:

-   -   cutting to size a piece from a continuous reinforcing band-like        element fed along a predetermined feeding direction;    -   approaching said piece to a previously cut piece along an        approach direction inclined with respect to the feeding        direction;    -   joining said piece to the previously cut piece;    -   repeating the cutting, approaching and joining steps until the        at least one reinforcing element is given a length determined        according to the length of the deposition region.

Advantageously, through the aforementioned steps it is possible toprovide a reinforcing element having a desired inclination of thethread-like reinforcing elements within it and a desired length startingfrom a continuous reinforcing element comprising thread-like reinforcingelements oriented substantially parallel to the longitudinal extensionthereof, as a continuous reinforcing element produced for examplethrough drawing and/or calandering processes, known to the man skilledin the art, can be.

Preferably, in the aforementioned joining step a piece is joined to thepreviously cut piece at respective joining sides parallel to the feedingdirection.

Preferably, the joining step comprises the step of partially overlappingthe pieces at the respective joining sides.

Preferably, in the cutting step the piece is cut according to a cuttingangle of between about 0° and about 70°.

More preferably, such a cutting angle is between about 20° and about65°.

In alternative embodiments of the process of the invention, it is alsopossible for the aforementioned approaching and joining steps of thepieces, and possibly also the cutting to size step, to be left out,reinforcing elements being provided that have been previously preparedand are already suitable, as to their structure and possibly also totheir length, for the subsequent deformation and deposition steps.

In a preferred embodiment of the process of the invention, the toroidalsupport has a rotation axis X-X and the step of deforming the at leastone reinforcing element comprises the steps of:

-   -   forming said annular reinforcing element closing the at least        one reinforcing element in a loop around the rotation axis X-X        so as to generate a substantially cylindrical surface, said        substantially cylindrical surface lying on a first laying        surface having, in a predetermined point thereof, a normal        extending along a first direction;    -   moving the substantially cylindrical surface from the first        laying surface to a second laying surface having, in a point        corresponding to said predetermined point on the first laying        surface, a normal extending along a second direction inclined        with respect to the first direction.

Advantageously, the deformation of the reinforcing element is thusachieved through a substantially geometric effect connected to thevariation of the lying position of a reinforcing element, previouslyclosed in a loop, as a whole. This type of deformation allows a highstructural homogeneity to be obtained in the deformed reinforcingelement, in particular as far as the final annular distribution of thereinforcing elements is concerned.

Preferably, the step of deforming the at least one reinforcing elementfurther comprises, after the step of forming the annular reinforcingelement and before the moving step, the step of changing the radialextension of the substantially cylindrical surface.

Preferably, the step of changing the radial extension of thesubstantially cylindrical surface comprises radially expanding such asubstantially cylindrical surface.

Advantageously, through this step it is possible to adapt the annularreinforcing element to deposition regions having different diameters.

Preferably, on the first laying surface the substantially cylindricalsurface is substantially coaxial with respect to the rotation axis X-Xof the toroidal support.

Preferably, on the second laying surface the annular reinforcing elementdefines a substantially frusto-conical surface having a longitudinalaxis coinciding with the longitudinal axis of the substantiallycylindrical surface.

These characteristics advantageously allow a deformed annularreinforcing element to be obtained in a simple and accurate manner, saidannular reinforcing element being ready to be deposited at a non-planarsubstantially annular deposition region, like that at the bead region ofa tyre.

Preferably, the deposition step is carried out during the moving step.

This advantageously allows the overall time taken to carry out thedeposition process to be reduced.

In a preferred embodiment of the process of the invention, it is alsoprovided the step of passing a pressing member on the deposited annularreinforcing element.

Advantageously, this further step ensures that the deposited annularreinforcing element adheres perfectly and along the entire surfacethereof to the underlying structures of the tyre being built.

Preferably, the deposition region is a substantially circular annularregion with an inner radius of between about 200 mm and about 350 mm.

Preferably, the at least one reinforcing element has a width of betweenabout 10 mm and about 50 mm.

Preferably, the at least one reinforcing element comprises at least onethread-like reinforcing element incorporated in an elastomeric material.

Preferably, at the end of the deposition step the at least onethread-like reinforcing element is orientated so as to form an anglegreater than or equal to 0° and less than 90° with a radial directionpassing through its own radially inner end.

In a second aspect thereof, the present invention refers to an apparatusfor depositing on a toroidal support a reinforcing element of a tyre forvehicle wheels, comprising:

-   -   at least one device for feeding a reinforcing element;    -   at least one deposition device suitable for forming an annular        reinforcing element and for depositing said annular reinforcing        element at a deposition region defined on the toroidal support;        wherein the at least one deposition device comprises a main body        and at least one mobile element associated with the main body        and actuatable to deform the annular reinforcing element so as        to give it a shape substantially corresponding to the shape of        the deposition region.

Such an apparatus can advantageously be used to carry out the process ofthe present invention described above.

In a preferred embodiment of the apparatus of the invention, the atleast one feeding device feeds a continuous reinforcing band-likeelement along to a predetermined feeding direction.

In this case, the apparatus of the invention preferably comprises atleast one cutting device for cutting to size pieces of the continuousreinforcing band-like element.

The apparatus of the invention also preferably comprises at least oneassembling device suitable for receiving such pieces and for allowingthem to be joined together to obtain said reinforcing element.

Advantageously, the at least one cutting device and the at least oneassembling device can cooperate with the feeding device, in the case inwhich it feeds a continuous reinforcing element, to form a reinforcingelement from which the annular reinforcing element to be subsequentlydeformed and deposited is obtained.

In alternative embodiments, it is nevertheless possible for the at leastone assembling device, and possibly also the at least one cuttingdevice, to be left out. In these cases the at least one feeding devicefeeds reinforcing elements that have been previously prepared and arealready suitable, as to their structure and possibly also to theirlength, for forming the annular reinforcing element.

Preferably, the at least one assembling device comprises a conveyor beltmovable along a conveying direction and suitable for sequentiallyreceiving the aforementioned pieces.

Preferably, the feeding direction of the at least one feeding deviceforms a feeding angle of more than 0° and less than 180° with such aconveying direction.

More preferably, such a feeding angle is equal to about 90°−α, where αis the cutting angle of the pieces from the continuous reinforcingband-like element.

Advantageously, this relative position between the at least one feedingdevice and the at least one assembling device allows a desired structureto be given, in a substantially automatic manner and with highflexibility, to the reinforcing element to be deposited, in particularas far as the arrangement and orientation of thread-like reinforcingelements provided therein are concerned.

In a preferred embodiment thereof, the at least one deposition devicecomprises a disc-shaped element rotatable about a respectivelongitudinal axis and is provided with a plurality of rotatable elementswhich can rotate about respective pin axes arranged around said rotationaxis, each of said rotatable elements comprising a seat for receiving aportion of the annular reinforcing element and being able to take up afirst operative position, wherein the receiving seat extends, withreference to said longitudinal axis, along a first direction, and asecond operative position, wherein the receiving seat extends, withreference to said longitudinal axis, along a second direction inclinedwith respect to the first direction.

Advantageously, the rotatable elements, through rotation thereof, allowthe deformation of the reinforcing element loaded on the depositiondevice to be obtained, moving such an element from the first layingsurface to the second laying surface, as described above with referenceto the process of the present invention.

Preferably, each of said pin axes is arranged at an axially inner edgeof said receiving seat.

Preferably, the rotatable elements are circumferentially arranged aroundthe longitudinal axis of the disc-shaped element and are radiallymovable with respect to such a longitudinal axis.

Advantageously, it is thus possible to vary the radial position of therotatable elements to radially deform the annular reinforcing elementand adapt it to deposition regions having different diameters.

Preferably, the rotatable elements comprise respective electromagnets.

Such electromagnets help in keeping the reinforcing element in positionduring the deformation and deposition step in the case where such anelement comprises steel thread-like reinforcing elements.

Preferably, the at least one deposition device is movable with respectto the toroidal support along a direction substantially coinciding witha rotation axis of said toroidal support.

Preferably, the apparatus of the invention further comprises a pressingmember suitable for exerting a pressure on the annular reinforcingelement deposited on said toroidal support.

In a preferred embodiment thereof, the apparatus of the inventioncomprises two feeding devices and two deposition devices provided forsubstantially simultaneously depositing two respective annularreinforcement elements at two deposition regions defined on axiallyopposite sides of the toroidal support.

Preferably, in this case, the apparatus also comprises two of theaforementioned cutting devices and two of the aforementioned assemblingdevices.

Further characteristics and advantages of the present invention shallbecome clearer from the following detailed description of a preferredembodiment of an apparatus and of a process according to the presentinvention, made hereafter with reference to the attached drawings. Insuch drawings:

FIG. 1 is a schematic top view of a deposition apparatus according tothe invention;

FIG. 2 is a partially sectional view in a generic radial plane of a tyrebeing built, that schematically shows a detail of a deposition device ofthe apparatus of FIG. 1 and action thereof according to the depositionprocess of the present invention;

FIG. 3 is a schematic perspective view of the deposition device of theapparatus of FIG. 1 placed near to a toroidal forming support;

FIG. 4 is a schematic perspective view with partially removed parts of adetail of the deposition device of FIG. 3;

FIG. 5 is a schematic partially sectional side view of the depositiondevice of FIG. 3;

FIG. 6 is a schematic top view with partially removed parts of thedeposition device of FIG. 3.

In FIG. 1, an exemplary embodiment of an apparatus for depositingreinforcing elements of vehicle tyres according to the present inventionis wholly indicated with reference numeral 100.

The apparatus 100 can, for example, be part of a work station of thetype described in document WO 01/36185 to the same Applicant.

In the exemplary embodiment described, the apparatus 100 is suitable formaking a reinforcing structure, operatively associated with annularanchoring structures 2 (only one of which is illustrated in FIGS. 2 and3) of a carcass structure 3 in the bead region of a tyre. Thereinforcing structure comprises at least one annular reinforcing element1′ formed and deposited as described hereafter. The specific axialposition of each annular reinforcing element 1′ with respect to theannular anchoring structures 2 can vary according to product therequirements of the; for example, the reinforcing structure can comprisea single annular reinforcing element 1′ between two layers of annularanchoring structures 2, or else in axially outer position with respectto the annular anchoring structures 2. It is also possible to provide areinforcing structure comprising many annular reinforcing elements 1′operatively associated, at different axial positions, with the annularanchoring structures 2.

The manufacturing of the reinforcing structure, as well as of the othercomponents and structures of the tyre being built, is advantageouslycarried out on a toroidal support 60, having an outer surface configuredsubstantially according to the inner configuration of the tyre to bemade and not described here in detail, since it can be made in anyconvenient way by the man skilled in the art. During the manufacture ofthe reinforcing structure the toroidal support 60 preferably rests,through a support shaft 61 coaxial to a rotation axis X-X, on suitablefixed supports 62.

A reinforcing element 1 is preferably formed from pieces 5 ofpredetermined length, obtained through cutting operations sequentiallycarried out on at least one continuous reinforcing band-like element 4,and then suitably joined. From the reinforcing element 1 an annularreinforcing element 1′ is then formed, which is then deposited at apredetermined substantially annular deposition region 7 defined on thetoroidal support 60 (FIG. 3), as shall be described in detail hereafter,with reference to a preferred embodiment of the process of theinvention.

In alternative embodiments, not described in detail here, a reinforcingelement 1 ready for use can be provided, having the desired structureand length. In this case the apparatus 100 may not comprise devicesspecifically intended for the formation of the reinforcing element 1from a continuous band-like element 4, as described later on, just asthe process of the invention may not provide specific steps intended forthe formation of the reinforcing element 1, by this meaning that such anelement has been separately provided upstream of the deposition process,according to ways known to those skilled in the art.

The continuous band-like element 4 and, consequently, the pieces 5 andthe reinforcing element 1 obtained from it, preferably comprise aplurality of thread-like reinforcing elements 6 (for the sake of clarityshown only in FIG. 1) made from metallic or textile materialincorporated in a matrix of elastomeric material. Within the continuousband-like element 4 such thread-like reinforcing elements 6 extendparallel to each other, substantially along the direction oflongitudinal extension of the continuous band-like element 4, whereaswithin the reinforcing element 1 the thread-like reinforcing elements 6extend substantially parallel to each other, but obliquely with respectto the direction of longitudinal extension of the latter (FIG. 1), withan inclination determined by the specific ways of cutting and joiningthe pieces 5. In the present description and in the subsequent claims,the expression “direction of longitudinal extension” of the continuousband-like element 4 or of the reinforcing element 1 is used to indicatethe line defining the longitudinal direction of such elements andpassing through the middle point of one of the two shorter end sides.

The width of the reinforcing element 1 is preferably between about 10 mmand about 50 mm, wherein about 25 mm is a particularly preferredoperative value.

As schematically represented in FIG. 1, the apparatus 100 comprises twofeeding devices 20 a, 20 b suitable for feeding respective continuousband-like elements 4, two cutting devices 30 a, 30 b suitable forcarrying out cutting to size operations on the continuous band-likeelements 4 to make the pieces 5, two assembling devices 40 a, 40 bsuitable for receiving the pieces 5 and for allowing them to be joinedtogether to form respective reinforcing elements 1, and two depositiondevices 50 a, 50 b suitable for receiving such reinforcing elements 1and for depositing them on the toroidal support 60.

The pairs of feeding devices 20 a, 20 b, cutting devices 30 a, 30 b,assembling devices 40 a, 40 b and deposition devices 50 a, 50 b areidentical to each other and are spatially arranged with respect to thetoroidal support 60 so as to allow the formation and substantiallysimultaneous deposition of annular reinforcing elements 1′ at both ofthe axially opposite bead regions of the tyre being built.

In the following description reference shall be made in particular to aone device for each of the aforementioned pairs, meaning that what saidis also valid for the other, unless specifically indicated otherwise.

The feeding device 20 a can be a feeding reel, as shown in FIG. 1, oranother equivalent device known to those skilled in the art, such as adrawing and/or calandering device. The feeding device 20 a feeds thecontinuous band-like element 4 according to a feeding direction F.

The assembling device 40 a preferably comprises a conveyor belt movablealong a conveying direction T towards the deposition device 50 a. Thisconveyor belt sequentially receives the pieces 5 cut through the cuttingdevice 30 a so that they are arranged on it in a side-by-siderelationship, so as to be able to make joins along sides parallel to thefeeding direction F, in this way forming reinforcing elements 1 ofpredetermined length.

According to the invention, the deposition device 50 a, as well as forreceiving the reinforcing elements 1, is suitable for deforming suchelements into annular reinforcing elements 1′ before deposition, toadapt them to the shape of the deposition region 7.

As shown in particular in FIGS. 3 and 5, the deposition device 50 acomprises a main body essentially consisting of a disc-shaped element 51rotatably associated with a substantially cylindrical support element 52provided, at a free end thereof on which the disc-shaped element 51 ismounted, with a flange 520. The disc-shaped element 51 and the supportelement 52 are coaxial with respect to a longitudinal axis X′-X′.

A plurality of rotatable elements 510 is associated with the disc-shapedelement 51 through respective support groups 511, which extendvertically in a substantially axial direction from a face of such adisc-shaped element 51. The rotatable elements 510 are associated withthe support groups 511 through pins 512, which define pin axes Z-Z aboutwhich the rotation of the rotatable elements 510 can take place. Thesupport groups 511 and the pin axes Z-Z are arranged substantiallycircumferentially around the longitudinal axis X′-X′.

Each rotatable element 510 comprises a respective receiving seat 513suitable for receiving a portion of the reinforcing element 1, which,once loaded on the deposition device 50 a, defines an annularreinforcing element 1′. The pin axes Z-Z extend at the axially inneredge of each receiving seat 513, whereas at the axially outer edge anabutment 514 is preferably formed for the annular reinforcing element1′. In the present description and in the subsequent claims, theexpressions “axially inner” and “axially outer” relative to componentsor parts of the deposition device 50 a refer to the operative positionof the deposition device 50 a in the proximity of the toroidal support60 upon deposition (FIGS. 2 and 3).

Each rotatable element 510 comprises, at the receiving seat 513, anelectromagnet 515, which in particular helps in keeping the annularreinforcing element 1′ in position during the deformation and depositionsteps, in the case where it comprises steel thread-like reinforcingelements 6.

As can be seen in particular in FIG. 2, each of the rotatable elements510 can rotate about the respective pin axis Z-Z between a firstoperative position and a second operative position, determining throughsuch a movement the deformation of the annular reinforcing element 1′,as shall be described more clearly hereafter with reference to apreferred embodiment of the process of the invention. In particular, inthe first operative position, corresponding to a rest configuration ofthe rotatable elements 510, the receiving seats 513 extend, withreference to the longitudinal axis X′-X′, along a first direction,preferably substantially parallel to such an axis, whereas in the secondoperative position, corresponding to a rotated configuration, thereceiving seats 513 extend, again with reference to said longitudinalaxis X′-X′, along a second direction inclined with respect to the firstdirection.

The support groups 511, and therefore the rotatable elements 510, arealso radially movable with respect to the disc-shaped element 51, toallow a radial deformation of the annular reinforcing element 1′. Theradial movement of the support groups 511 is achieved through a suitabledisplacing mechanism, which, in the embodiment described here, can beoperated through rotation (FIGS. 4, 5 and 6). Such a displacingmechanism comprises small shafts 517 extending parallel to thelongitudinal axis X′-X′ from each support group 511 and free to slide inrespective grooves 518 formed on a face of the disc-shaped element 51.The grooves 518 extend from the centre towards the periphery of thedisc-shaped element 51 inclined by a predetermined angle with respect tothe radial direction. In this way, a lateral thrust given to eachsupport group 511 through the rotation of an actuation disc 53operatively associated with the support groups 511 can determine amovement in the radial direction of such support groups 511 with respectto the disc-shaped element 51. The correct radial alignment of eachsupport group 511 during movement is ensured by radial guides 516, whichare fixed to the disc-shaped element 51 at radially inner ends thereofand rest upon the flange 520. The radial movement of the support groups511 and therefore of the rotatable elements 510 allows the diameter ofthe annular reinforcing element 1′ for deposition on the toroidalsupport 60 to be varied.

The deposition device 50 a is globally movable towards and away from thetoroidal support 60 along a direction substantially coinciding with therotation axis X-X thereof, as shown in FIGS. 1 and 3.

The deposition apparatus 100 preferably also comprises a conventionalpressing member (not shown in the figures) known to the man skilled inthe art, which can act upon the annular reinforcing element 1′ oncedeposited, so as to ensure the complete adherence thereof to theunderlying structures of the tyre being built.

With reference to FIGS. 1, 2 and 3 a preferred embodiment of thedeposition process of the invention that can be carried out through thedeposition apparatus 100 described above shall now be described.

As stated above, through the preferred embodiment of the depositionapparatus 100 it is possible to simultaneously deposit two annularreinforcing elements 1′ at respective substantially annular depositionregions 7 at the axially opposite bead regions of the tyre being built.Also in the description of the preferred embodiment of the process ofthe invention, for the sake of simplicity, reference shall be made tothe deposition of the annular reinforcing element 1′ on one of the twodeposition regions 7, being understood that the steps describedhereafter can be carried out simultaneously for deposition on the otherdeposition region 7 as well.

The deposition region 7 is substantially circular in shape, with thecentre lying on the rotation axis X-X of the toroidal support 60 and theinner radius preferably between about 200 mm and about 350 mm.

In a first step of the process a reinforcing element 1 of predeterminedlength, determined as a function of the length of the deposition region7, is provided. In the preferred embodiment described here, this isobtained by cutting to size pieces 5 from the continuous band-likeelement 4 and then suitably joining such pieces.

The continuous band-like element 4 is fed by the feeding device 20 a′according to the feeding direction F, substantially coinciding with thedirection of longitudinal extension of the continuous band-like element4, defined above. Each piece 5 is cut according to a cutting angle α ofbetween about 0° and about 70°, more preferably between about 20° andabout 65°, said cutting angle α being defined between the perpendicularto the direction of longitudinal extension and a cutting direction C.

The successively cut pieces 5 are then sequentially received by theassembling device 40 a, having the form of a conveyor belt moving alongthe conveying direction T. The conveying direction T, which defines thedirection along which the pieces 5 are arranged on the conveyor belt inside-by-side relationship, is inclined with respect to the feedingdirection F. In particular, the feeding direction F forms a feedingangle β of more than 0° and less than 180° with the conveying directionT. Preferably, the feeding angle β is linked to the cutting angle α bythe relationship β=90°−α. Typically, the cutting angle α and the feedingangle β are preset and remain constant during the entire depositionprocess.

At the same time as the deposition on the assembling device 40 a, eachpiece 5 is joined to the previously deposited piece 5. The joining iscarried out at adjacent sides parallel to the feeding direction F ofadjacent pieces 5 and provides for partial overlapping of such sides,preferably limited to an edge portion consisting of just elastomericmaterial, i.e. wherein no thread-like reinforcing elements are present.Alternatively, the pieces 5 can also be joined end to end.

The cutting, approaching and joining steps of the pieces 5 are repeateda predetermined number of times, until the reinforcing, element 1 isgiven the desired length.

In a subsequent step of the process, the reinforcing element 1 thusobtained is deformed so as to obtain the annular reinforcing element 1′with a shape substantially corresponding to the shape of the depositionregion 7.

In particular, firstly the reinforcing element 1 is closed in a loopcoaxially around the rotation axis X-X of the toroidal support 60—i.e.around the longitudinal axis X′-X′ of the deposition device 50 a,substantially coinciding with the rotation axis X-X—, so as to form asubstantially cylindrical surface defining the annular reinforcingelement 1′. This is in practice carried out by winding the reinforcingelement 1 onto the deposition device 50 a at the receiving seats 513 ofthe rotatable elements 510, and by joining the end portions of thereinforcing element 1′. The group of receiving seats 513 defines a firstlaying surface of the annular reinforcing element 1′ having, in apredetermined point, a normal N₁ extending along a first direction (FIG.2). Considering that, as described above, in the operative rest positionof the rotatable elements 510, the receiving seats 513 extendsubstantially parallel to the longitudinal axis X′-X′, the direction ofthe normal N₁ is substantially perpendicular to this axis.

After the formation of the annular reinforcing element 1′, thedeformation step can comprise a radial expansion step of the annularreinforcing element 1′, carried out through the radial displacement ofthe support groups 511 of the rotatable elements 510, as describedabove.

Then, the deformation step provides for the movement of the annularreinforcing element 1′, possibly radially expanded, from said firstlaying surface to a second laying surface having, in a pointcorresponding to the aforementioned predetermined point on the firstlaying surface, a normal N₂ (FIG. 2) extending along a directioninclined with respect to the direction of the normal N₁. This is inpractice carried out by moving the rotatable elements 510 from theiroperative rest configuration to the operative rotated configuration,wherein they define the second laying surface. In particular, therotatable elements 510 are made to rotate about the respective pin axesZ-Z by an rotation angle γ preferably between about 35° and about 80°.

Passing from the first to the second laying surface the annularreinforcing element 1′ is deformed by a geometric effect, thus forming asubstantially frusto-conical surface coaxial with respect to the axesX′-X′ ed X-X.

In a subsequent step of the process, the annular reinforcing element 1′deformed as described, is deposited at the deposition region 7.

The deposition is preferably carried out at the end of the moving stepof the annular reinforcing element 1′, having positioned the depositiondevice 50 a at a distance from the toroidal support 60 such that therotatable elements 510 at the end of their rotation come into abutmentagainst the toroidal support 60, so as to obtain an at least partialadherence of the annular reinforcing element 1′ to the underlyingstructures.

In order to ensure complete adherence, a step of passing a pressingmember (not shown) on the deposited annular reinforcing element 1′ isalso provided.

1-32. (canceled)
 33. A process for manufacturing tyres for vehiclewheels, comprising building, on a toroidal support, a carcass structurecomprising at least one carcass ply associated, at axially opposite endedges thereof, with annular anchoring structures, wherein building saidcarcass structure comprises forming at least one reinforcing structure,operatively associated with said annular anchoring structures throughdeposition on said toroidal support of at least one reinforcing elementat a deposition region defined on said toroidal support, and wherein thedeposition of said at least one reinforcing element comprises the stepsof: providing at least one reinforcing element having a lengthdetermined as a function of a length of said deposition region;deforming said at least one reinforcing element to form an annularreinforcing element having a shape substantially corresponding to theshape of said deposition region; and depositing the annular reinforcingelement at said deposition region.
 34. The process according to claim33, wherein providing said at least one reinforcing element comprisesthe steps of: cutting to size a piece from a continuous reinforcingband-like element fed along a predetermined feeding direction;approaching said piece to a previously cut piece along an approachdirection inclined with respect to said feeding direction; joining saidpiece to a previously cut piece; repeating said cutting, approaching andjoining steps until said at least one reinforcing element is given alength determined as a function of the length of said deposition region.35. The process according to claim 34, wherein, in said joining step,said piece is joined to the previously cut piece at respective joiningsides parallel to said feeding direction.
 36. The process according toclaim 35, wherein said joining step comprises partially overlappingpieces at said respective joining sides.
 37. The process according toclaim 34, wherein, in said cutting step, said piece is cut according toa cutting angle of between about 0° and about 70°.
 38. The processaccording to claim 37, wherein said cutting angle is between about 20°and about 65°.
 39. The process according to claim 33, wherein saidtoroidal support has a rotation axis, and the deforming step of said atleast one reinforcing element comprises the steps of: forming saidannular reinforcing element by closing said at least one reinforcingelement in a loop around said rotation axis so as to generate asubstantially cylindrical surface, said substantially cylindricalsurface lying on a first laying surface having, in a predetermined pointthereof, a normal extending along a first direction; and moving saidsubstantially cylindrical surface from said first laying surface to asecond laying surface having, in a point corresponding to saidpredetermined point on said first laying surface, a normal extendingalong a second direction inclined with respect to said first direction.40. The process according to claim 39, wherein the deforming step ofsaid at least one reinforcing element further comprises, after said stepof forming said annular reinforcing element and before said moving step,the step of changing a radial extension of said substantiallycylindrical surface.
 41. The process according to claim 40, wherein saidstep of changing the radial extension of said substantially cylindricalsurface comprises radially expanding said substantially cylindricalsurface.
 42. The process according to claim 39, wherein, on said firstlaying surface said substantially cylindrical surface is substantiallycoaxial with respect to said rotation axis.
 43. The process according toclaim 42, wherein on said second laying surface said annular reinforcingelement defines a substantially frusto-conical surface having alongitudinal axis coinciding with a longitudinal axis of saidsubstantially cylindrical surface.
 44. The process according to claim39, wherein said depositing step is carried out during said moving step.45. The process according to claim 33, further comprising the step ofpassing a pressing member on a deposited annular reinforcing element.46. The process according to claim 33, wherein said deposition region isa substantially circular annular region with an inner radius of betweenabout 200 mm and about 350 mm.
 47. The process according to claim 33,wherein said at least one reinforcing element has a width of betweenabout 10 mm and about 50 mm.
 48. The process according to claim 33,wherein said at least one reinforcing element comprises at least onethread-like reinforcing element incorporated in an elastomeric material.49. The process according to claim 48, wherein, at the end of saiddepositing step, said at least one thread-like reinforcing element isoriented so as to form an angle greater than or equal to 0° and lessthan 90° with a radial direction passing through a radially inner end ofsaid at least one thread-like reinforcing element.
 50. An apparatus fordepositing a reinforcing element of a tyre for vehicle wheels on atoroidal support, comprising: at least one feeding device of areinforcing element; and at least one deposition device suitable forforming an annular reinforcing element and for depositing said annularreinforcing element at a deposition region defined on said toroidalsupport, wherein said at least one deposition device comprises a mainbody and at least one rotatable element associated with said main bodyand actuatable to deform said annular reinforcing element so as toprovide a shape thereof substantially corresponding to a shape of saiddeposition region.
 51. The apparatus according to claim 50, wherein saidat least one feeding device feeds a continuous reinforcing band-likeelement along a predetermined feeding direction.
 52. The apparatusaccording to claim 51, comprising at least one cutting device forcutting to size, pieces of said continuous reinforcing band-likeelement.
 53. The apparatus according to claim 52, comprising at leastone assembling device suitable for receiving said pieces and forallowing them to be joined together to obtain said reinforcing element.54. The apparatus according to claim 53, wherein said at least oneassembling device comprises a conveyor belt movable along a conveyingdirection and capable of sequentially receiving said pieces.
 55. Theapparatus according to claim 54, wherein said feeding direction forms afeeding angle of more than 0° and less than 180° with said conveyingdirection.
 56. The apparatus according to claim 55, wherein said feedingangle is equal to about 90°−α, where α is a cutting angle of said piecesfrom said continuous reinforcing band-like element.
 57. The apparatusaccording to claim 50, wherein said at least one deposition devicecomprises a disc-shaped element rotatable about a longitudinal axis andprovided with a plurality of rotatable elements which can rotate aboutrespective pin axes arranged around said longitudinal axis, each of saidat least one rotatable element comprising a receiving seat of a portionof said annular reinforcing element and capable of taking up a firstoperative position, wherein said receiving seat extends, with referenceto said longitudinal axis, along a first direction, and a secondoperative position, wherein said receiving seat extends, with referenceto said longitudinal axis, along a second direction inclined withrespect to said first direction.
 58. The apparatus according to claim57, wherein each of said pin axes is arranged at an axially inner edgeof said receiving seat.
 59. The apparatus according to claim 57, whereinsaid rotatable elements are circumferentially arranged around thelongitudinal axis of said main body and are radially movable withrespect to said longitudinal axis.
 60. The apparatus according to claim57, wherein said rotatable elements comprise respective electromagnets.61. The apparatus according to claim 50, wherein said at least onedeposition device is movable with respect to said toroidal support alonga direction substantially coinciding with a rotation axis of saidtoroidal support.
 62. The apparatus according to claim 50, furthercomprising a pressing member suitable for exerting a pressure on anannular reinforcing element deposited on said toroidal support.
 63. Theapparatus according to claim 50, comprising two feeding devices and twodeposition devices provided for substantially simultaneously depositingtwo respective annular reinforcing elements at two deposition regionsdefined on axially opposite sides of said toroidal support.
 64. Theapparatus according to claim 63, comprising two cutting devices and twoassembling devices when said at least one feeding device feeds acontinuous reinforcing band-like element along a predetermined feedingdirection.